print_head_scripts(): string[]

Description

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Return value

string[]

Handles of the scripts that were printed.

Performance profile

How much work a call to print_head_scripts() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Moderate

Reads stored settings via get_site_option(), cached per request but not free on a cold cache.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

23–28

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 28.

Plugin surface

2 hooks

Third-party callbacks on 'wp_print_scripts', 'print_head_scripts' run inside this call, and their cost is not bounded by anything here.

Called by

3

3 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksdo_action()called directly
• optionnetwork optionget_site_option()one call below print_head_scripts()

Further down the call graph this can also reach cache, serialize, query and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 4 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost print_head_scripts() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 2

2 hooks fire while print_head_scripts() runs, in this order:

1. 1
   do_action( wp_print_scripts )actionline 2166 (+5 into the body)

   Fires before scripts in the $handles queue are printed.

2. 2
   apply_filters( print_head_scripts )filterline 2182 (+21 into the body)

   Filters whether to print the head scripts.

Uses · 6

• did_action()Retrieves the number of times an action has been fired during the current request.
• do_action()Calls the callback functions that have been added to an action hook.
• wp_scripts()Initializes $wp_scripts if it has not been set.
• script_concat_settings()Determines the concatenation and compression settings for scripts and styles.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• _print_scripts()Prints scripts (internal use only)

Used by · 3

• wp_font_library_render_page()Render the font-library page.
• wp_options_connectors_render_page()Render the options-connectors page.
• wp_print_head_scripts()Prints the script queue in the HTML head on the front end.

Source code

View on Trac ↗View on GitHub ↗

2161function print_head_scripts() {2162	global $concatenate_scripts;2163 2164	if ( ! did_action( 'wp_print_scripts' ) ) {2165		/** This action is documented in wp-includes/functions.wp-scripts.php */2166		do_action( 'wp_print_scripts' );2167	}2168 2169	$wp_scripts = wp_scripts();2170 2171	script_concat_settings();2172	$wp_scripts->do_concat = $concatenate_scripts;2173	$wp_scripts->do_head_items();2174 2175	/**2176	 * Filters whether to print the head scripts.2177	 *2178	 * @since 2.8.02179	 *2180	 * @param bool $print Whether to print the head scripts. Default true.2181	 */2182	if ( apply_filters( 'print_head_scripts', true ) ) {2183		_print_scripts();2184	}2185 2186	$wp_scripts->reset();2187	return $wp_scripts->done;2188}

Changelog

Introduced in 2.8.0. One change between 6.7.7 and 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/script-loader.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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